Method and a system for producing block bodies from loose material such as sphagnum

ABSTRACT

In the production of growth blocks of sphagnum there are considerable operational problems with the required compacting of the loose sphagnum, as both compaction worms and pistons may easily get stuck. Instead, the invention provides for the use of a suction technique, whereby the loose sphagnum (2) is sucked into a perforated pipe (34) in a suction chamber (28), whereby a marked compaction of the material is achievable without any use of mechanical devices. The compacted block material may be surrounded by a decomposable paper casing, which is laid in successively as a lining hose of air permeable paper. The compacted material can be delivered as a compact string (46) by successive projection movements of the suction chamber (28) for being cut into blocks (56), and the suction chamber can temporarily opened for free return movements into its initial position.

The present invention relates to a method of producing substrate blocks,primarily small blocks of sphagnum for the growing af cuttings and seedplants, and of the type consisting of a cylindrical block having anenvelope of paper or a similar material and and an associated filling ofsphagnum or a corresponding substrate material. Such blocks can beproduced by extrusion of a substrate string that is introduced into acasing tube and cut into pieces of suitable length, and it is commonpractice that the cylindrical blocks thus produced are mounted in ane.g. vacuum shaped cutting tray of thin plastic, arranged with pocketsfor receiving the blocks, normally with the blocks somewhat upstandingfrom the top side of the tray. When the young plants have grown to acertain extent the substrate blocks are transferred to plant pots havinga larger substrate volume, and the casing material is graduallydecomposed, such that the plant can then freely grow its roots out inthe plant pot.

It is already known that for the production of the substrate blocks itis possible to use machines operating roughly in the same manner ascigarette machines, but also being correspondingly very expensive,whereby they are entirely out of reach for even very large gardeningenterprises or for only average sized special factories for theproduction of such blocks. There is an expressed need for cheapermachines for use in average sized enterprises, and here it has beencustomary to use a machinery operating by axially pressing the substratematerial into the casing tube by means of either a conveying worm or acompaction piston.

Basically this is a simple technique, which can be applied withrelatively very simple means, but for one thing the machinery is ratherexpensive anyway, and for another thing it is well known to the skilledpeople that there are noticeable operational difficulties with thesemachines, because a pressing forward and compaction of a loose sphagnumlike material gives rise to big problems due to the coarse fibrouscharacter of the material. With the use of both a piston and a wormthere are frequent operational disturbances and stops, and the cheaper,yet still quite expensive machines in this group are thus largelyproblematic due to the coarse and sometimes even vary coarse structureof the substrate.

In connection with the present invention it has been realized that it ispossible to effect an operationally much safer stowing together of thesubstrate material in the casing tube with the use of highly simplemeans, viz. by using suction in stead of pressing. The casing tube maywell be made of air permeable material, this even applying to a herewell usable material which has in fact already been used as a casingmaterial, without, however, the said property of the material havingbeen paid particular attention or utilized in connection with thefilling in of the substrate. The casing tube can be advanced through avacuum zone, in which air is sucked in or rather out with such acapacity that the suction can be brought to propagate axially through afeeder conduit in a manner such that the material may be supplied bysuction in from a storage of loose substrate material, while in thesuction chamber it will be packed together with a force depending of theapplied vacuum. This provides for operational conditions quite differentfrom those associated with pressing means, as there will be no risk ofany jamming. The compaction of the material will take place successivelyfrom the suction end of the suction zone, and it has been found that theoperational safety can hereby be extremely high.

Once the block material has been built up in the suction zone the filledpaper tube may be further advanced by mechanical means, whereby blocksof a suitable length can be currently cut from the advanced materialstring, and these blocks may then be transferred for automatic mountingin receiver units such as cutting trays.

The invention, which is further defined in the appended claims and alsocomprises a system for carrying out the method, will now be described inmore detail with reference to the drawing, in which:

FIG. 1 is a schematic perspective view of a system according to theinvention,

FIG. 2 is a lateral view thereof,

FIG. 3 is an end view of a paper inlet station, and

FIG. 4 is an end view of a suction chamber in the system.

In the right hand side of FIG. 1 is shown an amount of sphagnum 2supplied on a conveyor belt 4 forwardly towards the end of a suctionfunnel 6, which projects from a conveyor pipe 8, optionally in acrosswise movable manner, such that by control means not shown it can bedisplaced for currently sucking away the arriving sphagnum by the actionof a suction blower 10 connected with the pipe 8 further ahead thereof.It is not decisive how the sphagnum is supplied to the suction pipe 8,when only there is arranged for a preferably continuous sucking in.

The pipe extends further through a folding zone 12, in which an airpermeable paper strip 14 supplied from a storage reel 16 is successivelywrapped about the pipe and continues into the pipe through a narrowannular slot 18 so as to form an inner lining hose in the furtherprojecting pipe, designated 20. In a gluing station 22 glue is appliedto a joining edge area of this hose, and the glue is set by the hosepassing through a heating station 24, such that thereafter the paper webis stabilized in its hose shape for further advancing inside the pipe20.

The introduction of the paper web 14 is also illustrated in FIG. 3,where it is shown that the pipes 8 and 20 meet so as to form the annularslot 18, holding means 26 being arranged for mutually centered fixing ofthe pipes in this area.

Thereafter the pipe 20 continues further into a suction chamber 28designed as a cylindrical housing consisting of two mutually separablehalf parts having a outer shell 30 and an internal tube or half tubeshell 32, these shells 32 in the joined condition of the two half partsforming a perforated tube 34 extending as a prolongation of the pipe 20,though with a slightly larger diameter. As shown in FIG. 2 the pipe 20is intruding into a part of the perforated tube 34, with light slide fittherein.

The suction chamber is suspended in a surrounding frame 36 and is,together with this frame, axially reciprocal by means of suitabledriving means such as cylinders 38. The connection between the frame 36and the suction chamber is established through opposite workingcylinders 40 cooperating with the respective halves of the suctionchamber, such that these can additionally be controlled to move awayfrom each other, as indicated by dotted lines in FIG. 4.

The suction chamber 28 or rather the two halves thereof are connected,through flexible hoses 42, with the suction side of the said suctionblower 10, the outlet or pressure side of which is connected with aseparator cyclone 44.

As further mentioned below, a rigid material rod or string 46 will beformed in the suction chamber 28 and brought forwardly to a receivertube 48, which continues into a cutting box 50, in which a knife 52controlled by a cylinder 54 will successively cut the material stringfor forming it into block bodies 56, FIG. 2. These bodies are conveyedthrough a funnel member 58 for being received in suitable receptacles, apreferred design of which will be indicated below.

In an initial start phase the paper web 14 is introduced through theannular slot 18 and is `fished` forwardly to the left end of the suctionchamber 28, FIGS. 1 and 2. This end is temporarily closed, whereby thesuction blower 10 will suck in air through the hoses 42, the wall of theperforated inner tube 34, the wall of the tubular portion of airpermeable paper located thereagainst, the interior of the pipe 20 andits continuation 8 in front of the annular slot 18, and finally (orrather in the first place) through the outer suction funnel 6. Thesupplied sphagnum 2 will thus be sucked forwardly for being deposited inthe suction chamber 28, where the sphagnum is positively compacted atthe left hand end and therefrom further to the right. Hereby a rigidstring 46 of paper wrapped, compacted sphagnum will be built up.

After this initial starting phase the cylinders 38 are actuated forpushing the suction chamber 28 towards the cutting box 50, whereby thesuction chamber, bringing along the sphagnum string as compactedtherein, causes this string to be introduced into the inlet tube 48 onthe cutting box 50, while also causing the surrounding paper casing tobe advanced and thus also the paper web 14 to be drawn forwardly andinto the pipe 20 through the annular slot 18.

Thereafter the cylinders 40 are actuated to draw the half parts of thesuction chamber from each other, i.e. to the positions shown in dottedlines in FIG. 4, in which the inner, perforated tube portions 32 fullyleave their engagement with the formed string 46, and then the cylinders36 are actuated for returning the thus separated half parts of thesuction chamber into their initial positions, in which they are againbrought together by means of the cylinders 40. Now the compactedmaterial string 46 as emerging from the left hand end of the suctionchamber will form a practically airtight plug against air being suckedin from this end of the suction chamber, such that thereafter the saidtemporary closing of this end will no longer be required. New material 2will be sucked in for compaction in immediate continuation of the stringportion 46 which has already been projected from the suction chamber 28,and it will be appreciated that in this manner, by successive movementsof the half parts of the suction chamber, it is possible to achieve astepwise projection of the paper wrapped material string 46 to thecutting unit 50.

The material is introduced at the right hand end of the perforated tube36 of the suction chamber as the tube 36 is moved forwardly over the endof the pipe 20, and this movement is to be stopped just before thesuction chamber would hereby leave this pipe end, confer the suctionchamber position shown in dotted lines in FIG. 2. The suction chambershould not be opened until the material has been compacted all over thelength of the chamber and a short distance into the mouthing of the pipe20, viz. such that the material string 46 will be self carrying betweenthe mouthings of the pipes 20 and 48 when the suction chamber is openedfor its return movement; it could be a possibility, however, that thestring should not be fully self-carrying, as the lower half part of thesuction chamber could be left unlowered by the returning of the suctionchamber.

It is a theoretical possibility that the suction chamber could be leftunopened or unseparated, such that it should not have to be movable ordivided in separate halves, viz. if the conveying of the material string46 is effected by separate means in front of the front end of thesuction chamber, e.g. by driving means including toothed wheels, theteeth of which intrude directly into the side of the string 46; it willnot be very important if the paper casing is hereby widely damaged, butit has been found that it is difficult in this manner to achieve a welldefined conveyance of the string 46, because of a pronounced frictionbetween this string and the inner side of the perforated tube 36. It isthis friction which is utilized for the already described, preferredconveying method.

With reference to the above it can be of importance to determine whenthe perforated tube 36 has been entirely filled out by compactedmaterial. This may be determined iteratively, but also with the use of asub pressure gauge connected to the suction connection between thesuction blower 10 and the suction chamber 28; the applied sub pressurewill rise noticeably when the material has been compacted to such anextent that the further sucking in of air is blocked essentially.

In principle, the delivery of the cut block members 56 may take placedirectly to respective receiver openings in receiving trays which aredisplaced stepwise and laterally in front of the cutting unit 50, but inpractice this has been found less attractive. In stead it is preferred,as shown in FIG. 1, to drop the cut block members 56 through the spoutportion 58 such that they fall down into funnel members 60 carried bysupporting means 62 conveyed chainlike along a path 64 crossing over alongitudinally extending conveyor 66, which carries along the saidreceiver trays 68 having receiving pockets 70. Above the conveying pathof the supporting means 62 there is provided a push-down station 72 withpusher pistons 74, which, by means of a working cylinder 76, areoperable to push down the block members 56 into the respective receiverpockets 70 in the underlying trays 68 as conveyed on the conveyor 66.The push-down pistons 74 are able to surpass the pressure necessary forpressing the block members 56 downwardly out of the funnel members 60.

In the cutting station 12 the effective cutting means may be a circularsaw, but in practice it will be preferred to make use of more adjacent,parallel process lines for concurrently filling substrate blocks intomore tray pockets, and if so it will be suitable to use a rapidlyreciprocal saw blade, which can cut more substrate strings at a time bya unitary cross feed of the saw blade.

The compactness of the formed block substrate is highly depending of theapplied suction pressure, and it can be suitable to make use of apressure regulator 43, either for a production of blocks having avarying density or for adjusting the density when the quality of the rawmaterial varies.

For successful tests of the principles of the invention an ordinaryhousehold vacuum cleaner has been used in connection with a 40 mmsuction pipe, i.e. it has proved sufficient to use a simple suctionblower as distinguished from a real vacuum pump. Of course, severalproduction strings would be serviceable from a common suction blower.

The building up of the block string af sphagnum or other substratematerial may of course take place also without any precedingintroduction of the air permeable web and casing material, though inthat case the tube 34 in the suction chamber 28 should be finelyperforated, and in some cases it is acceptable to deliver the string orblock material without the surrounding envelope. Alternatively a casingmaterial may be applied in connection with the block string leaving thetube after the chamber 28.

It is a further possibility that the chamber 28 and its downstream tubeoutlet can be arranged with a certain directional break from thedirection of the preceding feeding pipe, whereby it would be possible touse a piston in connection with an external working cylinder forpressing out the material from the chamber region, without the latterbeing opened.

It should be mentioned that the technique according to the invention maywell be used for similar block formation of materials other thansphagnum, also for other purposes.

I claim:
 1. A method of manufacturing compacted substrate material froma loose material comprising:suctioning the loose material through a pipeinto a suction chamber for deposition and compaction into the compactedsubstrate material within the suction chamber by suction applied througha perforated tube in the suction chamber to the loose material; andconveying the compacted substrate material from the suction chamber. 2.A method according to claim 1 further comprising:forming a plug of thecompacted substrate material in an outlet conduit of the suction chamberas part of compacting the material within the suction chamber.
 3. Amethod according to claim 1 further comprising:introducing an airpermeable web through an aperture in the pipe; forming a lining from theweb in an end portion of the pipe adjacent the suction chamber; andconveying the lining containing the compacted substrate material fromthe suction chamber by gripping the lining and moving the grippedlining.
 4. A method according to claim 3 further comprising:moving thesuction chamber in a forward direction with separable parts of thesuction chamber joined together to hold the lining containing thecompacted substrate material during movement in the forward direction;and moving the suction chamber with the parts separated in a rearwarddirection back to a starting position of the forward movement toposition the suction chamber for a repeat of the forward movement of thelining containing the compacted substrate material.
 5. A system formanufacturing compacted substrate material from loose materialcomprising:a pipe for suctioning the loose material from a loosematerial source to a perforated tube within a suction chambersurrounding a part of the pipe; a suction source coupled to the suctionchamber through the perforated tube for applying suction to the loosematerial; and a mechanism for discharging the compacted substratematerial from the suction chamber.
 6. A system according to claim 5wherein the mechanism for discharging comprises:the suction chamberhaving separable parts; a mechanism for axially reciprocating thesuction chamber in a forward direction to move the compacted substratematerial in the forward direction while the parts are closed and in arearward direction while the parts are open to reposition the parts toclose on the compacted substrate material; and a mechanism for openingand closing the parts.
 7. A system according to claim 5 wherein:the pipehas an aperture into which an air permeable web is introduced; and amechanism to form the web into an axially movable lining within the pipefor containing the compacted material inside the lining.
 8. A systemaccording to claim 5 wherein:a suction pressure regulator is providedbetween the suction source and the suction chamber.
 9. A method ofmanufacturing compacted sphagnum from a loose sphagnumcomprising:suctioning the loose sphagnum through a pipe into a suctionchamber for deposition and compaction into the compacted sphagnum withinthe suction chamber by suction applied through a perforated tube in thesuction chamber to the loose sphagnum; and conveying the compactedsphagnum from the suction chamber.
 10. A method according to claim 9further comprising:forming a plug of the compacted sphagnum in an outletconduit of the suction chamber as part of compacting the sphagnum withinthe suction chamber.
 11. A method according to claim 9 furthercomprising:introducing an air permeable web through an aperture in thepipe; forming a lining from the web in an end portion of the pipeadjacent the suction chamber; and conveying the lining containing thecompacted sphagnum from the suction chamber by gripping the lining andmoving the gripped lining.
 12. A method according to claim 11 furthercomprising:moving the suction chamber in a forward direction withseparable parts of the suction chamber joined together to hold thelining containing the compacted sphagnum during movement in the forwarddirection; and moving the suction chamber with the parts separated in arearward direction back to a starting position of the forward movementto position the suction chamber for a repeat of the forward movement ofthe lining containing the compacted sphagnum.
 13. A system formanufacturing compacted sphagnum from loose sphagnum comprising:a pipefor suctioning the loose sphagnum from a loose sphagnum source to aperforated tube within a suction chamber surrounding a part of the pipe;a suction source coupled to the suction chamber through the perforatedtube for applying suction to the loose sphagnum; and a mechanism fordischarging the compacted substrate material from the suction chamber.14. A system according to claim 13 wherein the mechanism for dischargingcomprises:the suction chamber having separable parts; a mechanism foraxially reciprocating the suction chamber in a forward direction to movethe compacted sphagnum in the forward direction while the parts areclosed and in a rearward direction while the parts are open toreposition the parts to close on the compacted sphagnum; and a mechanismfor opening and closing the parts.
 15. A system according to claim 13wherein:the pipe has an aperture into which an air permeable web isintroduced; and a mechanism to form the web into an axially movablelining within the pipe for containing the compacted sphagnum inside thelining.
 16. A system according to claim 13 wherein:a suction pressureregulator is provided between the suction source and the suctionchamber.